1. Field of the Invention
The present invention relates generally to methods for forming conductor layers within microelectronic fabrications. More particularly, the present invention relates to methods for forming corrosion inhibited conductor layers, optionally with enhanced bondability, within microelectronic fabrications.
2. Description of the Related Art
Microelectronic fabrications are formed from microelectronic substrates over which are formed patterned microelectronic conductor layers which are separated by microelectronic dielectric layers.
In the process of forming patterned microelectronic conductor layers for use within microelectronic fabrications, and in particular in the process of forming patterned terminal microelectronic conductor layers for use within microelectronic fabrications, from which patterned terminal microelectronic conductor layers are formed bond pads within microelectronic fabrications, it is desirable to assure that such patterned microelectronic conductor layers, and in particular such patterned terminal microelectronic conductor layers, are formed in a fashion such that there is inhibited corrosion when both forming and subsequently processing those patterned microelectronic conductor layers. Inhibited corrosion when forming and subsequently processing patterned microelectronic conductor layers within microelectronic fabrications is desirable insofar as there is typically formed more fully functional and reliable connections within microelectronic fabrications to patterned microelectronic conductor layers with inhibited corrosion.
It is thus towards the goal of forming within microelectronic fabrications microelectronic conductor layers with inhibited corrosion that the present invention is directed.
Various methods have been disclosed in the art of microelectronic fabrication for forming microelectronic conductor layers, including patterned terminal microelectronic conductor layers from which may be formed bond pads within microelectronic fabrications, with desirable properties within microelectronic fabrications.
For example, Lin et al., in U.S. Pat. No. 5,248,384, disclose a method for forming within a microelectronic fabrication a void free aluminum containing conductor layer which has been exposed to an oxygen containing plasma incident to employing the oxygen containing plasma for stripping a photoresist layer in the presence of the aluminum containing conductor layer within the microelectronic fabrication. The method employs, after the oxygen containing plasma stripping of the photoresist layer in the presence of the aluminum containing conductor layer, a rapid thermal annealing of the aluminum containing conductor layer at a temperature of from about 400 to about 550 degrees centigrade to provide the aluminum containing conductor layer void free.
In addition, Fukuyama et al., in U.S. Pat. No. 5,380,397, disclose a plasma etch method for forming within a microelectronic fabrication a patterned aluminum containing conductor layer with inhibited corrosion. The plasma etch method employs: (1) a halogen containing etchant gas composition for etching the patterned aluminum containing conductor layer from a corresponding blanket aluminum containing conductor layer; followed by (2) a hydrogen and oxygen containing etchant gas composition for simultaneously stripping from the patterned aluminum containing conductor layer: (a) a patterned photoresist layer employed in defining the patterned aluminum containing conductor layer; and (b) halogen residues which would otherwise facilitate corrosion of the patterned aluminum containing conductor layer.
Further, Jones et al., in U.S. Pat. No. 5,380,401, disclose a plasma etch method for removing from an aluminum containing conductor layer bond pad within a microelectronic fabrication a fluorine containing plasma etch residue formed incident to etching a silicon containing dielectric passivation layer formed over the aluminum containing conductor layer bond pad to form a via accessing the aluminum containing conductor layer bond pad. The plasma etch method employs an argon etchant gas, in conjunction with an optional carbon dioxide carrier gas, to etch from the aluminum containing conductor layer bond pad within the microelectronic fabrication the fluorine containing plasma etch residue.
Still further, Yachi, in U.S. Pat. No. 5,578,163, discloses a plasma etch method for forming within a microelectronic fabrication a sidewall residue free patterned aluminum containing conductor layer with inhibited corrosion of the sidewall residue free patterned aluminum containing conductor layer. The plasma etch method employs: (1) a first plasma employing a chlorine containing etchant gas for forming the patterned aluminum containing conductor layer from a corresponding blanket aluminum containing conductor layer, where the patterned aluminum containing conductor layer so formed has a sidewall residue layer formed thereupon; (2) a second plasma employing a hydrogen containing etchant gas composition for removing from the patterned aluminum containing conductor layer a chlorine containing residue formed incident to use of the first plasma; and (3) a third plasma employing an oxygen containing etchant gas composition for removing from the patterned aluminum containing conductor layer a patterned photoresist layer employed in defining the patterned aluminum containing conductor layer, where the second plasma and the third plasma are employed under temperature conditions such that the sidewall residue layer is not hardened and thus may be readily subsequently stripped.
Yet still further, Kim, in U.S. Pat. No. 5,595,934, discloses a method for inhibiting corrosion of an aluminum containing conductor layer bond pad within a microelectronic fabrication. The method employs forming upon the aluminum containing conductor layer bond pad an aluminum oxide coating while employing a simultaneous exposure of the aluminum containing conductor layer bond pad to ozone and ultraviolet radiation.
Analogously with Fukuyama et al., as cited above, Kawamoto, in U.S. Pat. No. 5,698,071, also discloses a plasma etch method for stripping from a patterned aluminum containing conductor layer formed within a microelectronic fabrication while employing a chlorine containing etchant gas composition a patterned photoresist layer employed in defining the patterned aluminum containing conductor layer while employing the chlorine containing etchant gas composition, while similarly inhibiting corrosion of the patterned aluminum containing conductor layer. The plasma etch method sequentially employs: (1) a first plasma employing an etchant gas composition comprising a substance having at least one of hydrogen and hydroxyl for stripping from the patterned aluminum containing conductor layer a chlorine containing residue which would otherwise corrode the patterned aluminum containing conductor layer, followed by; (2) a second plasma employing a second etchant gas composition comprising an oxygen containing etchant gas composition for stripping from the patterned aluminum containing conductor layer the patterned photoresist layer, wherein by employing the first plasma etch method and the second plasma etch method sequentially, there is provided process efficiency within the aggregate plasma etch method.
Finally, Fukazawa et al., in U.S. Pat. No. 5,744,402, disclose a method for forming within a microelectronic fabrication a residue free patterned layer while employing a plasma etch method, where the residue free patterned layer formed employing the plasma etch method may be a residue free patterned aluminum containing conductor layer formed employing a chlorine containing plasma etch method. The method employs, subsequent to the plasma etch method, a stripping of plasma etch residues from the patterned layer, such as the patterned aluminum containing conductor layer, while employing hydrofluoric acid vapor at a temperature of greater than about 40 degrees centigrade.
Desirable in the art of microelectronic fabrication are additional methods and materials which may be employed to form within microelectronic fabrications microelectronic conductor layers with inhibited corrosion.
It is towards that goal that the present invention is directed.
A first object of the present invention is to provide a method for forming a microelectronic conductor layer within a microelectronic fabrication.
A second object of the present invention is to provide a method in accord with the first object of the present invention, where the microelectronic conductor layer is formed with inhibited corrosion.
A third object of the present invention is to provide a method in accord with the first object of the present invention and the second object of the present invention, which method is readily commercially implemented.
In accord with the objects of the present invention, there is provided by the present invention a method for passivating a target layer. To practice the method of the present invention, there is first provided a substrate. There is then formed over the substrate a target layer, where the target layer is susceptible to corrosion incident to contact with a corrosive material employed for further processing of the substrate. There is then treated, while employing a first plasma method employing a first plasma gas composition comprising an oxidizing gas, the target layer to form an oxidized target layer having an inhibited susceptibility to corrosion incident to contact with the corrosive material employed for further processing of the substrate. Finally, there is then further processed, while employing the corrosive material, the substrate. Within the method of the present invention, the target layer may be a microelectronic conductor layer, such as but not limited to a patterned aluminum containing microelectronic conductor layer.
The present invention provides a method for forming a microelectronic conductor layer within a microelectronic fabrication, where the microelectronic conductor layer is formed with inhibited corrosion. The method of the present invention realizes the foregoing object by first forming over a substrate which may be employed within a microelectronic fabrication a target layer, where the target layer may be a patterned aluminum containing microelectronic conductor layer which is susceptible to corrosion incident to contact with a corrosive material employed for further processing of the substrate. There is then treated, while employing a first plasma method employing a first plasma gas composition comprising an oxidizing gas, the target layer to form an oxidized target layer having an inhibited susceptibility to corrosion incident to contact with the corrosive material employed for further processing of the substrate, prior to further processing, while employing the corrosive material, of the substrate.
The method of the present invention is readily commercially implemented. The present invention employs methods and materials as are generally known in the art of microelectronic fabrication. Since it is a process ordering and a process control which provides at least in part the present invention, rather than the existence of methods and materials which provides the present invention, the method of the present invention is readily commercially implemented.